Modern telecommunication networks comprise huge numbers of network nodes (network elements), and a great number of the nodes are switching elements such as cross-connects having a complex system of input and output ports. Each of the input and output ports usually comprises a plurality of connections and is characterized by various functions. For example, some output ports may serve for dropping portions of a signal, while other output ports provide a throughput of the inputted signal. The switching elements not only comprise various types of ports and connections, but usually have particular equipment limitations so that not each and every input connector can work with an arbitrary output connector of the same or other switching element in the network. There may be a number of reasons for such limitations, including differences in protocols, physical characteristics, incompatible locations in space, preferred or non-preferred connections, cost-related limitations etc.
For solving various tasks related to finding appropriate connections in the modern networks, the following hierarchy of management systems is usually provided and utilized:                a Network Management System (NMS) of the network, NMS having a network-wide view i.e., possessing information on types of all existing network nodes and their connections at the current moment,        an Element Management System (EMS) of a particular network element, EMS having an element-wide view i.e., holding information on various types of connections the network element (node) comprises, and on various equipment limitations the network element has.        
The NMS sees the network as a current configuration of the network nodes and may contact any node by contacting its EMS.
When a path is to be found between two points in the network, a program usually called pathfinder applies to the NMS for allocating such a path between the available network elements. Upon finding a preliminary path which, for example, is determined as a shortest path, a detailed connectivity pattern should be found via the elements planned for the path. To do that, the NMS applies to EMS of each node in the path to allocate specific connectivity solutions.
A similar method is described in EP 1130942A2, where the network manager queries a resource management mechanism to allocate an output port for an input port in an optical packet switching apparatus. The resource management mechanism then applies to a port availability database of a switching element, and upon reserving a spare output port, the optical switch control mechanism is activated.
The iterations between the NMS and each of the EMS are time consuming, require multiple exchange of protocols. Sometimes, the connectivity solution for a particular node cannot be found due to any of its equipment limitations unknown to the NMS, and a substantive portion of the pathfinder process must be repeated i.e., a number of searches, performed by the NMS in interaction with EMS, increases. As a result, the process requires more time and is inefficient.